var crypto = require('crypto');
var schemas = require("./schemas.js");
var _ = require("lodash");

var User = function(data) {
    this.data = data;
}

User.prototype.data = {}

User.prototype.get = function (name) {
    return this.data[name];
}

User.prototype.set = function (name, value) {
    this.data[name] = value;
}

User.prototype.sanitize = function (data) {
    data = data || {};
    schema = schemas.user;
    return _.pick(_.defaults(data, schema), _.keys(schema));
}

User.prototype.save = function (callback) {
    var self = this;
    this.data = this.sanitize(this.data);
    db.collection("users").update({username:username},this.data, callback(err, count));
}

// Function to look up a user document by the users username
User.getByUsername = function (username, callback) {
//     console.log("Getting user document for: "+username);
    db.collection("users").findOne({username:username}, function(err, doc) {
        callback(null, new User(doc));
    });
}

// Function to verify authentication via a username and password.
// Requires internal hashing function.
User.verify = function (username, password, callback) {
    console.log("Verifying user: "+username);
    db.collection("users").findOne({username: username}, function(err, doc) {
        if (err || !doc) {
            console.log("Username "+username+" does not exist");
            console.log(err);
            callback(err, null);
        }
        else {
//             console.log("Username "+username+" exists");
//             console.log(username + "'s salt is " + doc.salt);
            var hash = hashPassword(password, doc.salt);
            console.log(username+" is logging in with a hashed password of "+hash);
            db.collection("users").findOne({username: username, password: hash},
                function(err, doc) {
                    callback(err, doc);
            });
        }
    });
}

// Helper functions, internal to model

hashPassword = function(password, salt) {
  var hash = crypto.createHash('sha256');
  hash.update(password);
  hash.update(salt);
  return hash.digest('hex');
}


module.exports = User;